Officers attempted to arrest Thomas on Tuesday night near the Fullerton Transportation Center on South Pomona Avenue after responding to reports of someone breaking into cars. A fight ensued and other officers arrived to help, Goodrich said. Six officers were eventually involved in Thomas’ arrest, Goodrich said.

Thomas, a transient well-known to merchants and police officers in downtown Fullerton, was eventually rendered unconscious and taken to the hospital, where he was placed on life support.

“We have officers that deal with transient population of Fullerton on a regular basis,” Goodrich said. “Many of them were familiar with Mr. Thomas. To the best of my knowledge, there’s never been anything of this level of violence.”

Members of Thomas' family could not be reached for comment Monday night. But Thomas’ father, Ron, a retired Orange County sheriff’s deputy, has claimed officers used excessive force in subduing his son, who was unarmed, slight and of medium height.

Goodrich said the case has been forwarded to the Orange County district attorney’s office, which will determined if any crime was committed during the encounter between Thomas and the officers. A parallel investigation is underway by Fullerton police to determine whether the officers violated any departmental policy, he said.

“It’s a tragic and unfortunate circumstance,” Goodrich said. “Our condolences are with the family for their loss.”